drm/imx: convey the pixelclk-active and de-active flags from DT to the ipu-di driver

The 'de-active' and 'pixelclk-active' DT properties are evaluated
by of_parse_display_timing() called from  of_get_drm_display_mode(),
but later lost in the conversion from videomode.flags to
drm_display_mode.flags.
Enhance of_get_drm_display_mode() to also return the bus flags in a
separate variable, so that they can be passed on to the ipu-di
driver.

Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
diff --git a/include/drm/drm_modes.h b/include/drm/drm_modes.h
index a8164d2..48e1a56 100644
--- a/include/drm/drm_modes.h
+++ b/include/drm/drm_modes.h
@@ -459,7 +459,7 @@
 				   struct videomode *vm);
 void drm_bus_flags_from_videomode(const struct videomode *vm, u32 *bus_flags);
 int of_get_drm_display_mode(struct device_node *np,
-			    struct drm_display_mode *dmode,
+			    struct drm_display_mode *dmode, u32 *bus_flags,
 			    int index);
 
 void drm_mode_set_name(struct drm_display_mode *mode);